Clutching device for windshield wipers



Nov. 17, 1953 H. A. CHIVERS 2,659,465

CLUTCHING DEVICE FOR WINDSHIELD WIPERS Filed July 22, 1948 2 Sheets-Sheet l Nov. l 7, 1953 H. A. CHIVERS 2,659,465

CLUTCHING DEVIbE FOR WINDSHIELD WIPERS Filed July 22, 1948 2 Sheets-Sheet 2 3 E3 7 4 41 a A Z 33 3.2a Q 34 I 33 31 13 61 33 haw/"a? dawn )4 Jwm-xas CLUTCH-KING DEVICE FOR WINDSHIELD WIPERS Henry Albert Chivers, Balwyn, Victoria,

. Australia Application July 22, 1948, Serial No. 40,033

Claims priority, application Australia August '7, 1947 3 Claims. (Cl. 192-32) This invention relates to windscreen wipers for a suitablecasing it at one end of another coaxial automobile vehicles and the like, and has forits shaft 22 provided with a worm 23 engaging a general object to provide improved operating or worm wheel 24 also supported in said casting. driving means for such wipers whereby numerous The governor may be of any suitable type and practical advantages will be obtained, the more construction, for example it may comprise a cross salient advantages being silent and positive operabar 23 having a pair of arms pivoted thereto at tion, ability to obtain infinitely variable control of their inner ends and carrying friction pads at their the speed of the wiper according to requirements, outer ends to engage the inner periphery of casprovision for preventing the wiper from operat ing 2| when the rotation of shaft 22 exceedsa ing at a higher speed than a predetermined maxipredetermined rate. Springs may be associated mum and simplicity of construction and arrangewith the arms so as to prevent the pads receding ment of the operating means which have a minitoo far from the periphery of the casing.

mum of working parts, none of which are liable A flexible drive member 26' (Figure 3) may to derangement. lead from the worm wheel shaft to the linkage According to the invention, I apply the prinfor actuating the wiper arms. ciples of fluid drive in the operating means in a In order to start, stop and exercise variable manner which enables the before-mentioned and speed control over the operating mechanism, a various other desirable advantages to be obtained sleeve 2? may be mounted with ability to turn in as will be readily appreciated from the following relation to the Worm spindle 22 at one end theredescription and the accompanying drawings in of, this sleeve being operated by an arm 28 conwhich: nected by a flexible control cable 29 to a suitable Figure l is a sectional elevation of one embodiposition on the vehicle. The sleeve is provided ment of the invention. with a circumierentially inclined slot 3! to ac- Figure 2 is a cross sectional View on line Il-H cominodate a pin 32 outstanding from a spindle of Figure l. 33 so that by turning the sleeve in one direction, Figure 3 is an end view of the right hand side a ball 3i projecting at one end of the spindle enof Figure l. gages the adjacent end of the worm shaft 22 and Figure 4 is a sectional elevation showing a premoves it lengthwise so that the dog clutch IE, I! ferred practical form of the invention. will be engaged and, by continued movement, will Referring to Figures 1 to 3, I provide a driving bring the working face of the driven turbine 4 shaft 2 adapted to be driven from the vehicle eninto closer proximity with the working face of the gine by any appropriate connections. A driving driving impeller 3, overcoming the influence of impeller 3 is fixed on this shaft, while a driven spring l3. runner or turbine 4 is fixed upon a coaxial shaft Thus it will be apparent that when the dog 6, these two members 3 and t of a fluid coupling 35 clutch I6, I! is disengaged, the wiper will be out being disposed within a chamber 7 which is filled of action. By engagement of the dog clutch, with oil or suitable hydraulic fluid. The chamthe worm shaft 22 is connected to the driven flyber may be closed by a cover 3 through one end wheel and, subject to the extent of lengthwise of which the driven shaft 6 projects through an movement of the worm shaft, the driven runner oil seal 9, while the other end of the cover may 0 will be moved towards the driving impeller so be attached by screws 5 i to a flange outstanding that the speed of rotation of the worm shaft and from the driving flywheel. consequently the speed of operation of the wipers The inner or adjacent faces of the two flywheel will be increased until there is a predetermined members 3 and i are provided with suitable cups, minimum gap between the adjacent faces of the pockets or recesses I2 spaced circumterentially impeller and turbine members, whereupon maxiand of any appropriate size and shape. u pe d W ll be obtained. b

A spring I3 may be arranged so as to yield- The governor device [9 can be set to come into ingly urge the driven member 4 and its shaft 8 operation automatically in order to prevent the away from the driving impeller, such outward Wipers being operated beyond a predetermined movement being limited by an appropriate limit maximum wiping speed.

t is, It will be appreciated that the foregoing con- The aforesaid projecting end of the driven runstruction and arrangement will achieve the obner shaft may have a dog clutch element it for jects and advantages as before stated herein.

engaging a companion element I? on the hub is A further advantage is that sudden bursts of of a centrifugal governor it which is mounted in 5 acceleration in engine speed will be automatically compensated by slipping of the fluid turbine drive.

The same principles are utilized in the embodiment of Figure 4 which may be taken to represent a typical commercial design. In this case the main driving shaft may be screwed into a hub 4| of a cap member 42 secured to the driving impeller 3 and forming, with the latter, chamber 1 which encloses the driven runner 4, the latter being fast upon shaft 6 around which the driving wheel is rotatable. This embodiment dispenses with a dog clutch but employs a plate clutch, the driving plate 43 being fast on shaft Bwhile the driven plate 44 is rotatable about the adjacent end of shaft 6 and supported with ability for axial movement by pins 46 extending through holes in a flange 41 of an extension 2211 of worm shaft 22.

A centrifugal governor may comprisea ring member 48 encircling part 22a and pivotally retained thereto by a cross bar 49 which is of halfcircular shape in cross section, at least where it extends within the semi-circular end of a bore or passage in the part 22a. The cross bar pivot may thus act as a cam to the extent that as the ring 48 swings toward a position perpendicular to part 22a, due to centrifugal force, member 49 turns in its passage and applies lengthwise pressure to a rod which is slidable in the bore of part 22a.

A spring 52 may encircle shaft 6 between cap 42 and the driven runner 4 to prevent the latter from receding too far from the driving impeller 3.. Another spring 53 may encircle rod 5| between a shoulder on part 22a and the driven plate 44 of the clutch.

An adjustable stabilizer or damping device is preferably associated with the driving plate of the clutch and such device may take the form of a disc 56 having a screwed hub 51 for screwing into an aperture in a partition wall 58 of a main casing or housing 59. The periphery of the disc 56 may be toothed so as to mesh with an adjusting screw 6| the head of which is accessible from the exterior of the casing. Thus by manipulating this screw the working face of the disc which may carry a layer of friction material 56a may be brought into variable pressure contact with the adjacent face of driving plate 43.

The other parts of Figure 4 not specifically mentioned may be assumed to be the same as or equivalents for the parts illustrated in Figures 1 to 3 and are denoted by similar reference numerals.

The operational characteristics of the embodiment of Figure 4 are substantially the same as those of Figures 1 to 3. Thus to initiate operation worm shaft 22 is moved endwise to the left in order to engage the plates of the clutch. The,

worm shaft is thereby operatively connected to the driven flywheel 4 so that the wiper will be actuated at a speed depending primarily upon the extent of the gap between the driving and,

driven flywheels. As the speed of rotation increases, the governor ring 48 swings towards a perpendicular position thus imparting endwise movement through cam 49 to rod 5| which causes the entire clutch device and shaft 6 with its driven runner 4 to be moved in the same direction so that the gap between a turbine and an impeller member is increased.

It will thus be apparent that such an arrangement permits or positive operation of the wiper at relatively low engine speeds and constant wiping action at relatively high engine speeds, as the driven runner is moved away from the driving impeller as engine speed increases but is permitted to closely approach the driving impeller at low engine speeds.

It will also be apparent that the stabilizer or damping device 56 prevents excessive speed of operation of the wipers and that such device may be conveniently set so as to exercise its control function at any given speed of rotation.

Having now described my invention; what I claim as new and desire to secure by Letters Patent is:

1. Apparatus for operating a windscreen wiper, comprising a fluid coupling device having a driving impeller, means connecting said impeller to a source of power, said coupling device having a driven runner operatively associated with said driving impeller so as to provide a gap between the runner and impeller, means for adjusting the gap between the runner and impeller while the apparatus is in operation in order to vary the speed of rotation of the driven runner, and a device operatively associated with the runner for restraining excessive speed of operation of the apparatus and comprising a stationary member provided with a cylindrical surface and a centrifugal governor having pivoted arms terminating in pads adapted to engage said surface.

2. Apparatus for operating a windscreen. wiper, comprising a fluid coupling device having a driving impeller, a shaft on which said impeller is secured, said coupling device having a driven runner operatively associated with said driving impeller so as to provide a gap between the runner and impeller, a second shaft upon which said driven runner is secured extending in axial alignment with said first mentioned shaft, clutch elements for operatively interconnecting the second shaft with a driven shaft, and means for imparting lengthwise movement to said driven shaft in order to engage and disengage the clutch elements and for imparting lengthwise move ment to said second shaft in order to vary the gap between said impeller and runner while the clutch elements are interengaged.

3. Apparatus according to claim 2,and including a centrifugal governor mounted upon said driven shaft and means actuated by said governor, upon the speed of rotation exceeding a given rate, to impart lengthwise movement to the said second shaft, without disengaging the clutch elements, in order to increase the gap between the runner and impeller.

HENRY ALBERT CHIVERS.

References Cited in the file of this patent UNITED STATES PATENTS Number Name Date 1,672,232 Saives June 5, 1928 1,959,349 Dodge May 22, 1934 2,093,236 Dodge Sept. 14, 1937 2,129,366 Swennes Sept. 6, 1938 2,318,187 Addison, Jr. May 4, 1943 2,336,167 Dillon Dec. 7, 1943 2,395,047 Hanson Feb. 19, 1946 FOREIGN PATENTS Number Country Date 251,900 Great Britain May 13, 1926 

